The Internet and the Web

How they Work and Where the Hell is That File?

Directory Structure

In order to understand the Internet and the world wide web, one must first understand and be able to navigate their own computer.

All desktop, servers, or laptop computers function in essentially the same way. They store the Operating System (OS), application programs (APPS), and data on one or more Hard Disk Drives (HDD).

What this means is that each HDD contains thousands of data files that make up the OS, APPS, and user data files. It is important to remember that as far as the computer is concerned, it is all just raw data files. The structure of each file and the way it is loaded determines what it is.

All the files are stored in a series of layered directories. The top layer is referred to as “ROOT” and is the first place the computer looks for data.

The popular illustration has been to compare a computer system to an office. There is a desktop, a file cabinet full of folders, a wastebasket, and a telephone.

In this example, the file cabinet is the HDD and the desktop is the working memory (RAM) of the computer. The desktop is merely a view of what is running in RAM at that moment.

When the lights go out, the desktop (RAM) is wiped clean and everything that was on it is lost. Everything that was placed in the file cabinet (HDD) is still there.

That is why the term “folder” is used in many systems in place of the old term, “directory”. The two terms are interchangeable. For this article, we will continue to use directory or DIR.

Different Operating Systems use different file manager programs to examine the file and directory structure of a HDD. Various version of Windows uses a file manager program called Windows Explorer. Kubuntu Linux uses a file manager program called Dolphin. There many others.

All file managers will allow the user to see how files are stored on the HDD and allow them to delete, copy, or move files.

Note how the directories are shown first with sub-directories shown under each one. Imagine a file folder labeled Pictures with other folders inside of it labeled Family, Pets, and Vacation.

Using the file manager, you can move or copy files from one directory to another. For example, if one of your vacation pictures shows the family with some friends, you may want to copy that image file to the Family sub-directory so it can be found either way.

Once there is an understanding of the concept of moving files from one directory to another, we are halfway to understanding how the Internet works.

History

Much of the following document deals with history and terminology. It is useful in understanding why we use certain protocols and programs.

Back in the 1960s, military communications depended on the telephone and radio. In the case of a major war, both of these are fairly easy to interrupt. Researchers at ARPA (predecessor to DARPA) thought it would be possible to connect multiple computers in a network that would be easier to secure and more resilient in case of an attack.

In 1965 working with Thomas Merrill, Lawrence G. Roberts connected the TX-2 computer in Mass. to the Q-32 in California with a low speed dial-up telephone line creating the first (however small) wide-area computer network ever built.

The RAND group had written a paper on packet switching networks for secure voice in the military in 1964. It happened that the work at MIT (1961-1967), at RAND (1962-1965), and at NPL (1964-1967) had all proceeded in parallel without any of the researchers knowing about the other work.

By the end of 1969, four host computers were connected together into the initial ARPANET, and the budding Internet was off the ground.

File Transfer Protocol

When computers are connected in a network, it is possible to copy a file from one system to another using File Transfer Protocol (FTP). There are many ways to do this. One of the most popular is a free and open source application called Filezilla. It works in much the same way as a file manager program. It shows two windows side-by-side. One is the local HDD and the other is the remote server.

World Wide Web

In 1990 the first web server was setup at CERN by Tim Berners-Lee. It used a NeXT computer and had a message on the screen “This machine is a server. DO NOT POWER DOWN!” The HTML language is developed to display websites.

In 1993 CERN places the World Wide Web technology in the public domain. The first popular web browser was called Mosaic and the web starts to flourish.

The IMG tag is added to HTML code in order to display images.

Thus the World Wide Web (WWW) is born!

The point to all this is to show that websites are merely a collection of files on a server. In essence, they are no different than the files on a desktop computer.

ISPs and Web Hosts

When one moves into a new home, one of the first requirements is an Internet connection. This is your Internet Service Provider (ISP). This allows your computer to access websites and other

Internet resources.

If a personal or business website is needed, a hosting service (Host) is required.

HTML vs WordPress

These days there are many programming languages that can be used to develop a website.

The original one and still the basis for may sites is HyperText Markup Language (HTML). It is actually rather simple and easy to learn. Many web page designers in the past have developed marvelous sites using only a web browser, a text editor, and an FTP program.

More than 80% of the web servers in use today are called LAMP servers. LAMP stands for Linux, Apache, MySQL, and PHP. Linux is the operating system, Apache is a program that allows the system to support webpages, MySQL is a database program for controlling large amounts of related data, and PHP is another language that is similar to HTML. All of these are required on most modern websites.

WordPress is a sophisticated collection of files that acts as a visual front-end for the LAMP system. It enables someone who doesn’t have the time nor desire to learn all the background programming languages a modern, commercial website requires.

Besides the basic LAMP files, WordPress also makes use of Cascading Style Sheets (CSS). In the old days of pure HTML, if a website had multiple pages, the layout, colors, fonts, columns, etc. had to be coded for each page. If the owner wanted to change background color, then it had to be changed on every page in order to make the site appear uniform. When most websites were only a half-dozen pages, this wasn’t too much of a task.

Modern commercial websites with blogs routinely run to hundreds of pages. CSS helps Web developers create a uniform look across several pages of a Web site. Once the style is defined in cascading style sheet, it can be used by any page that references the CSS file.

When a website owner wants to change a “theme” in WordPress, they are actually installing a new set of CSS files. That is why all future pages added to the site share the same appearance.